Inductively coupled rf plasma source with magnetic confinement and faraday shielding

ABSTRACT

Disclosed is an inductively coupled RF plasma source that provides both magnetic confinement to reduce plasma losses and Faraday shielding to suppress parasitic capacitive components. The inductively coupled RF plasma system comprises an RF power source, plasma chamber, an array of permanent magnets, and an antenna array. The plasma chamber is comprised of walls and a dielectric window having an inner and outer surface wherein the inner surface forms a wall of the plasma chamber. The array of parallel conductive permanent magnets is electrically interconnected and embedded within the dielectric window walls proximate to the inner surface and coupled to ground on one end. The permanent magnet array elements are alternately magnetized toward and away from plasma in the plasma chamber to form a multi-cusp magnetic field. The antenna array may be comprised of parallel tubes through which an RF current is circulated. The antenna array is oriented perpendicular to the permanent magnet array.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention relate to the field of semiconductor devicefabrication. More particularly, the present invention relates to aninductively coupled RF plasma generating apparatus that is capable ofproviding both magnetic confinement and Faraday shielding.

2. Discussion of Related Art

Plasmas are used in a variety of ways in semiconductor processing toimplant wafers or substrates with various dopants, to deposit or to etchthin films. Such processes involve the directional deposition or dopingof ions on or beneath the surface of a target substrate. Other processesinclude plasma etching where the directionality of the etching speciesdetermines the quality of the trenches to be etched.

Generally, plasmas are generated by supplying energy to a neutral gasintroduced into a chamber to form charged carriers which are implantedinto the target substrate. For example, plasma doping (PLAD) systems aretypically used when shallow junctions are required in the manufacture ofsemiconductor devices where lower ion implant energies confine thedopant ions near the surface of the wafer. In these situations, thedepth of implantation is related to the bias voltage applied to thewafer. In particular, a wafer is positioned on a platen, which is biasedat a negative potential with respect to the grounded plasma chamber. Agas containing the desired dopant materials is introduced into theplasma chamber. A plasma is generated by ionizing the gas atoms and/ormolecules.

Once the plasma is generated, there exists a plasma sheath between theplasma and the surrounding surfaces, including the workpiece. The sheathis essentially a thin layer at the boundary of the plasma which has agreater density of positive ions (i.e. excess positive charge) ascompared to the bulk plasma which is electrically neutral. The platenand substrate (e.g., wafer for doping applications) are then biased witha negative voltage in order to cause the ions from the plasma to crossthe plasma sheath. During crossing of the sheath the ions acquire akinetic energy equal with the potential drop across the sheath.Therefore the ions are implanted into the wafer at a depth proportionalto the applied bias voltage. The ion dose implanted into the waferdetermines the electrical characteristics of the implanted region andthe uniformity of the dose across the wafer surface ensures that alldevices on the semiconductor wafer have identical operatingcharacteristics within specified limits. Each of these parameters arecritical in the semiconductor fabrication process to ensure that alldevices have the desired operating characteristics.

RF powered plasma sources can be capacitively coupled, inductivelycoupled or wave coupled (helicons). In capacitive coupling, theelectrons in the plasma are accelerated directly by local electricfields generated at the surface of the electrodes by an RF power supplytypically operating in the MHz range (0.4-160 MHz). Because the electricfields are oriented normal to the electrode surface they also accelerateions that impact the electrode surface or a dielectric surfacepositioned in front of the electrode. Ion impact to the electrode ordielectric dissipates energy resulting in less energy for plasmageneration. Moreover, ion impact to the electrode or dielectric causesan undesirable sputtering of the surface impacted. Sputtering is aprocess whereby atoms are ejected from a solid surface due tobombardment of the target by energetic particles. Capacitively coupledRF plasma sources also suffer from other disadvantages. For instance,the electrodes sometimes release unwanted impurities into the plasma. Inaddition, capacitively coupled RF plasma sources provide low plasmadensity therefore are less suitable for ion sources applications.

In inductive coupling, the plasma electrons are accelerated in adirection parallel to a current carrying antenna by an electric fieldresulting from an induced magnetic field according to theMaxwell-Faraday equation

${\nabla{\times \overset{->}{E}}} = {- \frac{\partial\overset{->}{E}}{\partial t}}$

where, Ē denotes electric field and {right arrow over (B)} is themagnetic field. The current in the antenna is generated by an RF powersupply. Inductive coupling is more efficient than capacitive couplingsince most of the coupled energy is dissipated through electroncollisions with a neutral gas. A voltage proportional to the length andinductance of the antenna is developed across the antenna that induces aparasitic capacitive coupling to the plasma. Parasitic capacitance is anunwanted capacitance that can exist between two electronic componentssimply because of their proximity to each other. This creates theaforementioned undesirable additional power dissipation and materialsputtering. However, the capacitive component can be suppressed byinserting a Faraday shield between the antenna and the plasma.

A Faraday shield is a device that is designed to block and focuselectric fields. Such a Faraday shield may comprise an array of groundedconductors orthogonal to the antenna currents. The Faraday shield isdesigned to terminate the electric fields while allowing the magneticfields to propagate.

Inductively coupled plasma generation configurations can be divided intotwo categories—those utilizing an internal antenna and those utilizingan external antenna. For internal antenna configurations the antenna(i.e., inductive coupler) is immersed into the plasma chamber traversingthe chamber walls by way of localized vacuum feed-throughs. For externalantenna configurations the antenna is positioned outside of the plasmachamber separated by a dielectric window.

It is advantageous to provide magnetic confinement to the inner surfaceof the plasma chamber to reduce plasma losses to the walls. This enablesa higher plasma density driven by less RF power and further providesoperation at lower neutral gas pressure as well as higher plasmauniformity. Magnetic confinement is typically achieved by distributingmulti-cusp magnets just outside the plasma chamber walls. Internalantenna configurations allow better magnetic confinement than externalantenna configurations but preclude the use of a Faraday shield.External antenna configurations place the antenna behind a dielectricwindow which interferes with the application of multi-cusp magneticconfinement on a significant portion of the plasma chamber surface area(i.e., the dielectric window).

Thus, a trade-off exists between internal and external antennaconfigurations in that an external antenna configurations allows the useof a Faraday shield inside the plasma chamber, but does not allow formagnets to provide plasma confinement and an internal antennaconfiguration allows the use of magnets for better plasma confinement,but does not provide for a Faraday shield.

Accordingly, the embodiments disclosed and claimed herein are animprovement to the art and describe a method and apparatus that providesboth Faraday shielding and magnetic confinement for an inductivelycoupled RF plasma source.

SUMMARY OF THE INVENTION

In an embodiment there is disclosed an inductively coupled RF plasmasystem that provides both magnetic confinement to reduce plasma lossesand Faraday shielding to suppress parasitic capacitive components. Theinductively coupled RF plasma system comprises an RF power source forgenerating an RF current, a plasma chamber, an array of permanentmagnets, and an antenna (or an antenna array). The plasma chamber iscomprised of walls and a dielectric window having an inner and outersurface wherein the inner surface forms a wall of the plasma chamber.The array of parallel conductive permanent magnets is electricallyinterconnected and embedded within the dielectric window proximate tothe inner surface and coupled to ground on one end. The permanent magnetarray elements are alternately magnetized toward and away from plasma inthe plasma chamber to form a multi-cusp magnetic field. The antennaarray is comprised of parallel tubes through which an RF current iscirculated. The antenna array is contained in a plane that is orientedperpendicular to the permanent magnets' magnetization vector.

In another embodiment, an inductively coupled RF plasma system thatprovides both magnetic confinement and Faraday shielding includes an RFpower source for generating an RF current and a plasma chamber operativeto be pumped down and then filled with a reactive gas that can beionized and transformed into a plasma. The plasma chamber includes adielectric window having an inner and outer surface wherein the innersurface forms a wall of the plasma chamber. A permanent cusp magnetarray is electrically interconnected and coupled to ground on one endand is embedded within the dielectric window in a magnetic cusp geometrythat is proximate to the inner surface. An antenna coupled with the RFpower source and includes an elongated tube through which the RF currentis circulated. The antenna is oriented perpendicular to the permanentmulti-cusp magnets' magnetization vector.

In another embodiment, a method of providing magnetic confinement andFaraday shielding to an inductively coupled RF plasma source includesproviding an RF power source for generating an RF current and providinga plasma chamber operative to be pumped down and then filled with areactive gas that can be ionized and transformed into a plasma. Theplasma chamber is comprised of walls and a dielectric window having aninner and outer surface wherein the inner surface forms a wall of theplasma chamber. An electrically conductive permanent cusp magnet arrayis embedded within the dielectric window proximate to the inner surfaceof the dielectric window. The permanent cusp magnet array is coupled toground at one end and the permanent cusp magnet array is alternatelymagnetized toward and away from the plasma in the plasma chamber to forma multi-cusp magnetic field. An antenna (or an antenna array) is coupledwith the RF power source where the antenna array includes parallelelongated tubes external to the dielectric window such that the antennaarray is oriented perpendicular to the permanent multi-cusp magnetsmagnetization vector. An RF current is circulated through the antenna(or antenna array) to induce a variable magnetic field inside thechamber and implicitly to generate an electric field able to ionize thegas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a illustrates a cross-sectional block diagram of a plasma sourceaccording to an embodiment of the invention.

FIG. 1 b illustrates the construction of the dielectric window accordingto an embodiment.

FIG. 1 c illustrates the orientation between an array of antennae and anarray of magnets.

FIG. 2 illustrates a first more detailed cross-sectional block diagramof a section of the plasma source in FIG. 1.

FIG. 3 illustrates a second more detailed second cross-sectional blockdiagram of a section of the plasma source that is offset 90 degrees fromFIG. 2.

FIG. 4 is a graph illustrating the decay of a multi-cusp magnetic fieldin the direction ψ.

FIG. 5 illustrates a partial cross-sectional block diagram of a sectionof the dielectric window showing geometrical features of the magneticmulti-cusp configuration.

DESCRIPTION OF EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention, however, may be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, like numbers refer to like elements throughout.

As previously mentioned, inductively coupled plasma generationconfigurations can be divided into two categories—those utilizing aninternal antenna and those utilizing an external antenna. For internalantenna configurations the antenna (i.e., inductive coupler) is immersedin the plasma chamber traversing the chamber walls by way of localizedvacuum feedthroughs. For external antenna configurations the antenna ispositioned outside of the plasma chamber separated by a dielectricwindow.

It is advantageous to provide magnetic confinement to the inner surfaceof the plasma chamber to reduce plasma losses to the walls. This enablesa higher plasma density driven by less RF power and further allowsoperation at lower neutral gas pressure as well as higher plasmauniformity. Magnetic confinement is typically achieved by distributingmulti-cusp magnets just outside the plasma chamber walls.

Internal antenna configurations provide better magnetic confinement thanexternal antenna configurations but preclude the use of a Faradayshield. External antenna configurations place the antenna behind avacuum window which interferes with the application of multi-cuspmagnetic confinement on a significant portion of the plasma chambersurface area (i.e., the dielectric window). The embodiments describedbelow demonstrate an apparatus that uses an external antenna array toprovide RF inductive coupling in which both magnetic confinement andFaraday shielding can be achieved.

FIG. 1 a illustrates a cross-sectional block diagram of a plasma source5 according to an embodiment of the invention. A plasma chamber 10 isdefined by walls 7 that are sealed by a dielectric window 12 to create avolume. Vacuum pumping is accomplished through a slit 8 by a pumpingsystem (not shown) comprised of turbomolecular pumps backed by roughingpumps. Slit 8 also serves for the extraction of the ion beam. Gasfeed-through openings 20 in walls 7 allow the working gas to becontinuously introduced into the plasma chamber 10 to maintain theplasma and replenish the consumed gas. The gas by-products followingplasma decomposition are continuously pumped out through slit 8. Theworking gas may be, for example, BF3, B2H6, PF3, PH3, GeF4, AsF3 etc.,depending on the desired dopant nature.

Embedded within the dielectric window 12 is a permanent cusp magnetarray 14 that runs perpendicular to an antenna array 16 that ispositioned outside the dielectric window 12. Being electricallyconductive and grounded the permanent multi-cusp magnet array 14 forms aFaraday shield. The antenna array 16 is driven by an RF power source 9.The RF power source 9 (which includes an RF generator and a matchingnetwork) typically operates in the frequency range of 0.4 MHz-160 MHz.The variable magnetic field generated by the RF current (I_(rf)) throughthe antenna array 16 induces a local electric field in the plasmachamber. As a result the free electrons gain energy and ionize workinggas atoms and/or molecules through ionization collisions. The magnets inthe permanent cusp magnet array 14 may be an alloy comprised of but notlimited to, aluminum, nickel and cobalt (Al—Ni—Co), samarium cobalt(Sm—Co), or neodymium, iron, and boron (Nd—Fe—B). For the purpose ofhigh magnetic flux-energy product, other permanent magnets such as thosecomposed of rare earth alloys might be used. The characteristics thepermanent magnets should exhibit include high magnetic strength, highoperation temperature, and electrical conductivity.

FIG. 1 b illustrates the construction of the dielectric window 12according to an embodiment. The dielectric window 12 can be formed intwo (2) layers. There is a first layer 12 a of width w1 in whichparallel grooves 12 b are machined. The grooves 12 b are adapted toreceive the permanent cusp magnets that comprise array 14. There is alsoa second thinner layer 12 c of width w2. The thinner layer 12 c isbonded to layer 12 a thereby separating the permanent cusp magnet array14 from the plasma 11. The dielectric material may comprise, but is notlimited to, alumina, aluminum nitride, quartz, or sapphire.

FIG. 1 c illustrates an orientation between the antenna array 16 and thepermanent cusp magnet array 14. The antenna array 16 and the permanentcusp magnet array 14 are oriented perpendicular to one another. Whilenot illustrated in FIG. 1 c, the antenna array 16 and the permanent cuspmagnet array 14 are separated by the dielectric window 12 described withreference to FIG. 1 b above. FIG. 1 c is intended to show orientationonly. The electrically conductive permanent cusp magnet array 14 formsthe Faraday shield. Because the electrically conductive permanent cuspmagnet array 14 is oriented perpendicular to the antenna array 16, itprovides no conductive path that is parallel to the antenna array 16 andthus does not interfere with the variable magnetic field penetrationinto the plasma provided by antenna array 16 driven by RF power supply9.

FIG. 2 illustrates a more detailed cross-sectional block diagram of asection of the plasma source 5 shown in FIG. 1 a. In this illustration asection of a plasma source 5 is shown in which the RF current (I_(rf))flowing through the antenna array 16 is oriented perpendicular to thepaper plane and the permanent multi-cusp magnet array 14 is orientedwith its magnetization vector in the plane of the paper. Similarly, FIG.3 illustrates a more detailed second cross-sectional block diagram of asection of the plasma source 5 in FIG. 1 that is offset 90 degrees fromFIG. 2. In this illustration a section of a plasma source 5 is shown inwhich both the permanent magnet array 14 magnetization vector and the RFcurrent (I_(rf)) flowing through antenna array 16 are in the plane ofthe paper.

Referring to both FIGS. 2 and 3, the antenna array 16 is positionedoutside of the plasma source and may be in thermal contact with thedielectric window 12 of the plasma chamber. Because dielectric window 12is heated by the ion bombardment process during normal operation, byplacing the antenna array 16 in thermal contact with the dielectricwindow 12, the antenna array 16 acts as a cooling mechanism by sinkingsome of the heat in the dielectric window 12. Embedded in the dielectricwindow 12 is the permanent cusp magnet array 14 that is orientedperpendicular to the antenna array 16 and is positioned near the innersurface of the plasma chamber. As was illustrated in FIG. 1 b thepermanent cusp magnet array 14 is embedded within the grooves 12 b ofthe first dielectric window layer 12 a and then bonded to the seconddielectric window layer 12 c. In addition, the permanent cusp magnetarray 14 may be comprised of electrically conductive strong permanentmagnets. The antenna array 16 is generally comprised of parallel tubesthrough which RF current is circulated. In an alternative embodiment asingle tube can comprise the antenna array 16. The RF current isgenerated by RF source 9 typically operating between 0.4-160 MHz.

As illustrated, the antenna array 16 is separated from the plasma 11 bythe dielectric vacuum window 12. The plasma has been generated usinginductive coupling in which the plasma electrons are accelerated in adirection parallel to the current through the antenna 16 by an electricfield resulting from an induced variable magnetic field according to

${\nabla{\times \overset{->}{E}}} = {- {\frac{\partial\overset{->}{E}}{\partial t}.}}$

The permanent cusp magnet array 14 that runs perpendicular to theantenna array 16 is magnetized alternately toward and away from theplasma 11 thereby forming a multi-cusp magnetic field 13 that losesstrength as it penetrates to a depth d into plasma 11. The permanentcusp magnet array 14 is also electrically conductive (or made to beelectrically conductive with a metallic coating) and electricallyinterconnected, the whole array being coupled to ground 21 at one endthereby forming a Faraday shield to suppress parasitic capacitivecoupling components. Since the permanent magnet array 14 provides noconductive path that is parallel to the antenna array 16 there is nointerference with the variable magnetic field penetration into theplasma.

In constructing the plasma chamber it is desirable to avoid directcontact of the permanent cusp magnet array 14 with plasma 11. Directcontact of the permanent cusp magnet array 14 with plasma could resultin plasma contamination and excessive heating to the permanent cuspmagnet array 14. Plasma contamination refers to the introduction ofunwanted impurities to the plasma that can wind up being deposited onthe work piece to which the plasma ions will be subjected. Excessiveheating of the permanent cusp magnet array 14 may cause non-uniformweakening of the magnetic strength and/or eventual demagnetization.

Avoiding direct contact of the permanent cusp magnet array 14 withplasma 11 may be achieved by constructing the dielectric vacuum window12 that separates them in two (2) layers. There is a first layer inwhich grooves are machined to accept the permanent cusp magnet array 14and a second thinner layer bonded to the first layer which separates thepermanent cusp magnet array 14 from the plasma 11. It is also desirablethat the permanent cusp magnet array 14 be cooled because the dielectricvacuum window 12 is heated by the plasma 11 during normal operation.

Cooling the permanent cusp magnet array 14 can be achieved by runningthe discharge with the cooled antenna array 16 that is in thermalcontact with the dielectric vacuum window 12. By placing the antennaarray 16 in thermal contact with the dielectric window 12, the antennaarray 16 can act as a cooling mechanism of sorts by sinking some of theheat in the permanent cusp magnet array 14 within the dielectric window12.

It is also desirable that the magnetic confinement takes place close tothe inner surface of the dielectric vacuum window 12 within a distancerange d that is smaller than the plasma skin depth 6 so that the RFenergy is deposited within the confined plasma volume shown in FIGS.2-5. The plasma skin depth 6 is shown in FIGS. 2-5 with reference toline 15 and refers to the depth in plasma to which the maximum RF powercan be transmitted. Magnetically confining the plasma is desirablebecause it reduces the wall losses and implicitly increases theionization efficiency. For plasma uniformity, it is desired that thecusp magnetic field not penetrate deep in the plasma. To keep themagnetic confinement close to the inner surface of the dielectric window12, the magnetic cusp geometry should have a small pitch.

On the other hand, to have an effective magnetic confinement it isimportant to locate the permanent cusp magnet array 14 as near aspossible to the inner surface of dielectric window 12. A large magneticfield gradient is generated in the proximity of the dielectric window 12that will not interfere with the RF power deposition that occurs deeper(approximately to skin depth 6) in the plasma 11.

The magnetic field decays exponentially from the surfaces of thepermanent cusp magnet array 14 having a characteristic distance equal toapproximately 1/Π of the pitch. FIG. 4. is a graph illustrating thedecay of a multi-cusp magnetic field in the direction (ψ) that isperpendicular to the chamber wall where (d) is the distance at whichpoint the magnetic cusp field is no longer efficient in trapping chargedparticles and (δ) is the plasma skin depth, the distance where themaximum power deposition occurs.

As a rule of thumb, optimal magnetic confinement is obtained when thepitch of the magnetic cusp configuration equals the width of the magnet.For instance, for ⅜″ magnet width and ⅜″ pitch, in one example, Sm—Comagnets having a field-energy product of 2630 MGÖe yield a fieldstrength of approximately 500 Gauss at approximately 2.5 cm from themagnet surface. This is derived from the equation:

${B(\psi)} = {\frac{2B_{0}w}{\Delta}{\exp \left( {{- \pi}\frac{\psi}{\Delta - w}} \right)}}$

where B is the magnetic field strength at distance ψ in the directionperpendicular to the window, B₀ is the magnetic field strength at themagnet surface, Δ is the pitch of the magnetic cusp configuration and wis the width of the permanent magnet.

FIG. 5 illustrates the geometrical variables that drive the magneticfield strength and the penetration depth. The magnetic field strength atdistance (ψ) is calculated using a pitch (Δ) shown as the distancebetween successive permanent magnets 14 in which each permanent magnet14 is of width w. Magnetic field directional lines 17 are shown betweenthe alternating poles of successive permanent magnets 14 which penetratethrough dielectric window 12 into the plasma chamber 10.

While the present invention has been disclosed with reference to certainembodiments, numerous modifications, alterations and changes to thedescribed embodiments are possible without departing from the sphere andscope of the present invention, as defined in the appended claims.Accordingly, it is intended that the present invention not be limited tothe described embodiments, but that it has the full scope defined by thelanguage of the following claims, and equivalents thereof.

1. An inductively coupled RF plasma system that provides both magneticconfinement and Faraday shielding, the inductively coupled RF plasmasystem comprising: an RF power source for generating an RF current; aplasma chamber operative to be filled with a working gas that can beused to create a plasma; a dielectric window having an inner and outersurface wherein the inner surface forms a wall of the plasma chamber; apermanent cusp magnet array comprised of parallel elements that areelectrically interconnected and coupled to ground on one end that isembedded within the dielectric window in a magnetic cusp geometry thatis proximate to the inner surface; and an antenna array coupled with theRF power source and comprised of parallel elongated tubes through whichan RF current is circulated, wherein the antenna array is orientedperpendicular to the permanent cusp magnet array.
 2. The inductivelycoupled RF plasma system of claim 1 wherein the permanent cusp magnetarray elements are alternately magnetized toward and away from theplasma in the plasma chamber to form a multi-cusp magnetic field.
 3. Theinductively coupled RF plasma system of claim 1 wherein the permanentcusp magnet array elements are comprised of permanent magnets comprisedof magnetic alloys containing aluminum, nickel and cobalt (Al—Ni—Co),samarium cobalt (Sm—Co), or neodymium, iron, and boron (Nd—Fe—B).
 4. Theinductively coupled RF plasma system of claim 1 wherein the antennaarray is in thermal contact with the outer surface of the dielectricwindow.
 5. The inductively coupled RF plasma system of claim 1 whereinthe dielectric window is further comprised of: a first dielectric layerincluding a plurality of parallel grooves adapted to receive theelements of the permanent cusp magnet array; and a second thinnerdielectric layer that is bonded to the first layer thereby separatingthe permanent cusp magnet array from the plasma.
 6. The inductivelycoupled RF plasma system of claim 1 wherein the dielectric materialcomprising the dielectric window is comprised of one of alumina,aluminum nitride, quartz, or sapphire.
 7. The inductively coupled RFplasma system of claim 1 wherein the magnetic cusp geometry has a smallpitch.
 8. An inductively coupled RF plasma system that provides bothmagnetic confinement and Faraday shielding, the inductively coupled RFplasma system comprising: an RF power source for generating an RFcurrent; a plasma chamber operative to be filled with a working gas thatcan be used to create a plasma; a dielectric window having an inner andouter surface wherein the inner surface forms a wall of the plasmachamber; a permanent cusp magnet array comprised of parallel elementsthat are electrically interconnected and coupled to ground on one endthat is embedded within the dielectric window in a magnetic cuspgeometry that is proximate to the inner surface; and an antenna coupledwith the RF power source and comprised of an elongated tube throughwhich the RF current is circulated, wherein the antenna is orientedperpendicular to the permanent cusp magnet array.
 9. The inductivelycoupled RF plasma system of claim 8 wherein the permanent cusp magnetarray elements are alternately magnetized toward and away from theplasma in the plasma chamber to form a multi-cusp magnetic field. 10.The inductively coupled RF plasma system of claim 8 wherein thepermanent cusp magnet array elements are comprised of permanent magnetscomprised of magnetic alloys containing aluminum, nickel and cobalt(Al—Ni—Co), samarium cobalt (Sm—Co), or neodymium, iron, and boron(Nd—Fe—B).
 11. The inductively coupled RF plasma system of claim 8wherein the antenna is in thermal contact with the outer surface of thedielectric window.
 12. The inductively coupled RF plasma system of claim8 wherein the dielectric window is further comprised of: a firstdielectric layer including a plurality of parallel grooves adapted toreceive the elements of the permanent cusp magnet array; and a secondthinner dielectric layer that is bonded to the first layer therebyseparating the permanent cusp magnet array from the plasma.
 13. Theinductively coupled RF plasma system of claim 8 wherein the magneticcusp geometry has a small pitch.
 14. The inductively coupled RF plasmasystem of claim 8 wherein the dielectric material comprising thedielectric window is comprised of one of alumina, aluminum nitride,quartz, or sapphire.
 15. A method of providing magnetic confinement andFaraday shielding to an inductively coupled RF plasma source, the methodcomprising: providing an RF power source for generating an RF current;providing a plasma chamber operative to be filled with a working gasthat can be used to create a plasma; providing a dielectric windowhaving an inner and outer surface wherein the inner surface forms a wallof the plasma chamber; embedding an electrically conductive permanentcusp magnet array comprised of parallel elements within the dielectricwindow proximate to the inner surface of the dielectric window; couplingthe permanent cusp magnet array to ground on one end; alternatelymagnetizing the elements of the permanent cusp magnet array toward andaway from the plasma in the plasma chamber to form a multi-cusp magneticfield; and coupling an antenna array with the RF power source, theantenna array comprised of parallel elongated tubes external to thedielectric window such that the antenna array is oriented perpendicularto the permanent cusp magnet array.
 16. The method of claim 15 furthercomprising: circulating the RF current through the antenna array toinduce an electric and magnetic field within the plasma chamber.
 17. Themethod of claim 15 further comprising: placing the antenna array inthermal contact with the outer surface of the dielectric window.
 18. Themethod of claim 15 wherein the permanent cusp magnet array elements arecomprised of a magnetic alloy containing aluminum, nickel and cobalt(Al—Ni—Co), samarium cobalt (Sm—Co), or neodymium, iron, and boron(Nd—Fe—B) or any other rare earth magnetic alloys.
 19. The method ofclaim 15 wherein the dielectric material comprising the dielectricwindow is comprised of one of alumina, aluminum nitride, quartz, orsapphire.